<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .one{
            width:500px;
            height:300px;
            background-color:red;
          /*  margin-left:100px; */   /*两个盒子整体向右移动*/

            /*包含合并，解决问题的办法
             1、给父盒子设置边框；
             2、给父盒子设置overflow:hidden;
            */
           /* border:1px solid red;*/
            overflow:hidden;
        }
        .two{
            width:200px;
            height:200px;
            background-color:pink;
            /*margin-left:100px;*/
            margin-top:100px;
        }
    </style>
</head>
<body>
    <div class="one">
        <div class="two"></div>
    </div>
</body>
</html>